The two miners trapped Monday at the Buck Mountain Drift Mine operated by D. &. F. Deep Mine Coal Co. in Cass Township are at Geisinger Medical Center, Danville.
T.J. Kennedy, 25, is listed serious condition and Justin Reninger, mid-30s, as critical, said Kristen Hepler, an administrative assistant in the corporate communications department for the hospital.
Numerous fire companies and ambulances and the state Department of Environmental Protection responded to the scene Monday. The men were taken away in ambulances and flown by MedEvac to Geisinger.
Colleen Connolly, northeast regional spokeswoman for the DEP, said Tuesday she did not know where the men are from.
She provided more information about the roof collapse Monday.
In an email, Connolly said the accident occurred as miners from S. &. J. Coal Co., which owns the land, were working in the mine and were installing face props to hold up the wall or ceiling.
"After removing one of the props in order to improve the fit, a slab in the section of roof broke loose and collapsed onto the workers," Connolly wrote.
She does not know who removed the prop.
The men were trapped down 600 feet in the mine for "minutes," Connolly said.
Both Reninger and Kennedy are experienced miners with seven years of experience, she said
Other workers took them to the surface.
She said the men complained of "shoulder and back pain and contusions, and bruising."
"It appears accidental but were looking into everything," she said.
When asked if any procedures were not followed, she said that is something the agencies are examining.
Officials from state DEP Deep Mine Safety and Mine Health and Safety are investigating the collapse, Connolly said.
A call to the owner of D. & F. Deep Mine Coal Co. was not returned Tuesday.